In the prior art, as a process for preparing tetrahydropyran-4-ol, a method for producing tetrahydropyran-4-ol by reacting 3-buten-1-ol and formalin in the presence of a large amount of sulfuric acid with yield of 61% (based on 3-buten-1-ol) has been disclosed (Chem. Ber., 88, 1053 (1955)). This method involves, however, problems that yield is low, and a post-treatment of the sulfuric acid after completion of the reaction becomes complicated, or the like, and it was not advantageous as an industrial preparative process.
An object of the present invention is to solve the above-mentioned problems, and to provide an industrially preferred process for preparing tetrahydropyran-4-ol which requires no complicated post treatment, and can produce tetrahydropyran-4-ol with high yield.